Recently, the release 13 standard is trying to reflect a licensed assisted access (LAA, commonly called LTE-U) which is a service making use of an unlicensed band (e.g., 5 Giga Hertz (GHz)) in long term evolution (LTE). Also, LTE release 12 is already supporting discovery reference signal (D-RS) or radio interface-based synchronization (RIBS), etc. Accordingly, synchronization in not only an existing terminal but also a small cell base station, etc. has become a very important function.
A synchronization process is a process in which, when a terminal or small cell base station powers on, the terminal or small cell base station finds a symbol boundary, a frame boundary with an adjacent base station in order to provide a data service. By finding the symbol boundary, frame boundary, the terminal or small cell base station can get cell IDentification (CID) information of each base station in a situation in which several base stations exist.
In a case where several cell identifications exist and a symbol and frame synchronization by each cell identification is different, a synchronization system searches the symbol and frame synchronization by cell identification, and detects a cell identification in a synchronization and non-synchronization cell identification detection method. In this case, when searching a frame synchronization by cell identification, the synchronization system can be influenced by a cell identification having strong transmission power. The cell identification having the strong transmission power can lead to an increase of a search failure signal, deteriorating the symbol and frame synchronization and the performance of cell identification detection. Particularly, there is a difference of a time point of reception of a base station synchronization signal and thus, the more the power of an interference signal escaping a cyclic prefix (CP), accurate symbol synchronization estimation is not achieved, so performance deterioration can take place.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.